Pore inducer and porous abrasive form made using the same

ABSTRACT

Various embodiments disclosed relate to pore inducers and porous abrasive forms made using the same. In various embodiments, the present invention provides a method of forming a porous abrasive form including heating an abrasive composition including pore inducers to form the porous abrasive form. During the heating the pore inducers in the porous abrasive form reduce in volume to form induced pores in the porous abrasive form.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a national stage filing under 35 U.S.C. 371 ofPCT/US2017/032111, filed May 11, 2017, which claims the benefit of U.S.Provisional Application No. 62/339,546, filed May 20, 2016, thedisclosures of which are incorporated by reference in their entiretiesherein.

BACKGROUND

A typical way to create porosity in a vitrified grinding wheel is toblend in randomly-shaped naphthalene particles into a mixture ofabrasive, glass frit, temporary binders, and water. The mix is pressedin a steel mold to the desired shape. The abrasive wheel or form is thenplaced into a low temperature oven to sublime out the naphthalene andharden the temporary binder. The wheel or form is then placed into afurnace to vitrify the bond (e.g., 700-1100° C.). The resulting wheelhas a very porous structure that is desired for certain grindingapplications. The pores aid in chip and swarf removal during thegrinding operation as well as help transport coolant to the grindingzone. However, naphthalene is toxic and is subject to environmentalregulations.

SUMMARY OF THE INVENTION

In various embodiments, the present invention provides a method offorming a porous abrasive form. The method includes heating an abrasivecomposition including pore inducers, to form the porous abrasive form.During the heating the pore inducers in the porous abrasive form reducein volume to form induced pores in the porous abrasive form.

In various embodiments, the present invention provides a method offorming a porous vitreous abrasive form. The method includes heating anabrasive composition including pore inducers including hollow glassfiller, to form the porous vitreous abrasive form. During the heatingthe pore inducers in the porous vitreous abrasive form reduce in volumeto form induced pores in the porous vitreous abrasive form.

In various embodiments, the present invention provides a porous abrasiveform. The porous abrasive form includes pore inducers that have reducedin volume to form induced pores in the porous abrasive form.

In various embodiments, the present invention provides a pore inducer.Upon heating within a medium the pore inducer reduces in volume in themedium to form an induced pore in the medium.

In various embodiments, the present invention can provide certainadvantages over other porous abrasive forms, pore inducers, and methodsof using the same, at least some of which are unexpected. In variousembodiments, the pore inducers of the present invention can form aporous abrasive form from an abrasive composition with less or no use ofnaphthalene. In various embodiments, the pore inducers of the presentinvention can release less or no toxic materials during pore formation,as compared to other processes including the use of naphthalene. Invarious embodiments, the pore inducers of the present invention canprovide better control over the size of induced pores, the shape ofinduced pores, or a combination thereof, as compared to other methods offorming pores, such as methods including the use of naphthalene. Invarious embodiments, the pore inducers of the present invention canprovide pores of a controlled shape and size without the typicaldistributions inherent to using pore-forming materials not derived froma mold. In some embodiments, the porous abrasive form of the presentinvention has better characteristics than other porous abrasive forms,such as better abrasive capabilities, better coolant flow, morecustomizable abrasive capabilities, longer service life, or acombination thereof.

BRIEF DESCRIPTION OF THE FIGURES

The drawings illustrate generally, by way of example, but not by way oflimitation, various embodiments discussed in the present document.

FIGS. 1A-B illustrate images of shaped pore inducers at variousmagnifications, in accordance with various embodiments.

FIGS. 2A-B illustrate scanning electron microscope (SEM) images of poresformed by naphthalene pore inducers.

FIGS. 3A-C illustrate SEM micrographs pores in vitrified test barsresulting from shaped pore inducers, in accordance with variousembodiments.

FIGS. 4A-B illustrate photomicrographs of the vitrified test bar formedusing shaped pore inducers, in accordance with various embodiments.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to certain embodiments of thedisclosed subject matter, examples of which are illustrated in part inthe accompanying drawings. While the disclosed subject matter will bedescribed in conjunction with the enumerated claims, it will beunderstood that the exemplified subject matter is not intended to limitthe claims to the disclosed subject matter.

Throughout this document, values expressed in a range format should beinterpreted in a flexible manner to include not only the numericalvalues explicitly recited as the limits of the range, but also toinclude all the individual numerical values or sub-ranges encompassedwithin that range as if each numerical value and sub-range is explicitlyrecited. For example, a range of “about 0.1% to about 5%” or “about 0.1%to 5%” should be interpreted to include not just about 0.1% to about 5%,but also the individual values (e.g., 1%, 2%, 3%, and 4%) and thesub-ranges (e.g., 0.1% to 0.5%, 1.1% to 2.2%, 3.3% to 4.4%) within theindicated range. The statement “about X to Y” has the same meaning as“about X to about Y,” unless indicated otherwise. Likewise, thestatement “about X, Y, or about Z” has the same meaning as “about X,about Y, or about Z,” unless indicated otherwise.

In this document, the terms “a,” “an,” or “the” are used to include oneor more than one unless the context clearly dictates otherwise. The term“or” is used to refer to a nonexclusive “or” unless otherwise indicated.The statement “at least one of A and B” has the same meaning as “A, B,or A and B.” In addition, it is to be understood that the phraseology orterminology employed herein, and not otherwise defined, is for thepurpose of description only and not of limitation. Any use of sectionheadings is intended to aid reading of the document and is not to beinterpreted as limiting; information that is relevant to a sectionheading may occur within or outside of that particular section.

In the methods described herein, the acts can be carried out in anyorder without departing from the principles of the invention, exceptwhen a temporal or operational sequence is explicitly recited.Furthermore, specified acts can be carried out concurrently unlessexplicit claim language recites that they be carried out separately. Forexample, a claimed act of doing X and a claimed act of doing Y can beconducted simultaneously within a single operation, and the resultingprocess will fall within the literal scope of the claimed process.

The term “about” as used herein can allow for a degree of variability ina value or range, for example, within 10%, within 5%, or within 1% of astated value or of a stated limit of a range, and includes the exactstated value or range.

The term “substantially” as used herein refers to a majority of, ormostly, as in at least about 50%, 60%, 70%, 80%, 90%, 95%, 96%, 97%,98%, 99%, 99.5%, 99.9%, 99.99%, or at least about 99.999% or more, or100%.

The term “resin” as used herein refers to a curable material, such as apolymer that can be crosslinked during curing, or a monomer that iscapable of being polymerized during curing. A resin can be a naturalresin, a synthetic resin, or a chemically modified natural resin. Aresin can be a thermoplastic material or a thermosetting materials.

The term “cure” as used herein refers to exposing to radiation in anyform, heating, or allowing to undergo a physical or chemical reactionthat results in hardening or an increase in viscosity. A flowablethermoplastic material can be cured by cooling it such that the materialhardens. A flowable thermoset material can be cured by heating orotherwise exposing to irradiation such that the material hardens.

Method of Forming a Porous Abrasive Form.

Various embodiments of the present invention provide a method of forminga porous abrasive form. The method can include heating an abrasivecomposition including pore inducers. During the heating the poreinducers can reduce in volume to form induced pores in the porousabrasive form. Although during the heating one or more components of thepore inducer may volatilize (e.g., transform to a gas via sublimation orboiling), these one or more components of the pore inducer are no longerin the porous abrasive form and are not to be considered in thedetermination of volume reduction of the pore inducer in the porousabrasive form. To determine the volume reduction of the pore inducer inthe medium, the beginning volume of the pore inducer in the abrasivecomposition is compared to the final volume of the remaining poreinducer in the porous abrasive form.

The method can include forming the abrasive composition; in someembodiments, the abrasive composition is already formed before themethod is performed. Forming the abrasive composition can includecombining one or more components of the abrasive composition to form theabrasive composition. The abrasive composition can be a substantiallyhomogeneous composition. Forming the abrasive composition can includeadding the pore inducers to the abrasive composition. The pore inducerscan be substantially homogeneously distributed in the abrasivecomposition.

The method can include forming the pore inducers; in some embodiments,the pore inducers are already formed before the method is performed.Forming the pore inducers can include curing a pore inducer startingmaterial to provide the pore inducer. Forming the pore inducers caninclude placing the pore inducer starting material composition in a moldprior to the curing (e.g., heating, irradiating, light, or a combinationthereof). The curing can be performed while the pore inducer startingmaterial composition is in the mold. The method can further includeremoving the pore inducers from the mold after the curing.

The abrasive composition that is heated can be a pressed abrasivecomposition. The method can include pressing the abrasive compositionbefore the heating; in some embodiments, the abrasive composition isalready pressed before the method begins. The pressing can be anysuitable pressing that compresses the abrasive composition, such aspressing in a mold. The pressing can include application of any suitableamount of pressure to the abrasive composition for any suitable timesuch that the abrasive composition is compressed to a higher density,such as a pressure of about 0.001 kg/mm² to about 1,000 kg/mm², about0.1 kg/mm² to about 10 kg/mm², about 0.001 kg/mm² or less, or about0.001 kg/mm² or less, or less than, equal to, or more than about 0.005kg/mm², 0.01, 0.05, 0.1, 0.2, 0.4, 0.6, 0.8, 1, 1.2, 1.4, 1.6, 1.8, 2,2.5, 3, 4, 5, 6, 7, 8, 9, 10, 50, 100, 500, or about 1,000 kg/mm² ormore.

The heating (e.g., “firing”) can be any suitable heating, such that theporous abrasive form is generated from the abrasive composition. Theheating causes a volume reduction in the pore inducers to form pores. Inaddition, the heating can cause a physical change or chemical change inone or more other components of the abrasive composition, such as abonding or binding of various components of the abrasive composition.The heating can cause vitrification of one or more components of theabrasive composition, such that the resulting porous abrasive form is aporous vitrified abrasive form, wherein the vitrification includesformation of “vitrified bonds,” “vitreous bonds,” “ceramic bonds,”“glass bonds” in the porous abrasive form. The heating can cause curingof one or more resinous components of the abrasive composition, suchthat the porous abrasive form includes a cured resin; if the resin is amajor component of the abrasive composition compared to vitrifyablecomponents the heating can form a porous resinoid abrasive form. Theheating can include melting or softening of metal components in theabrasive composition. The heating can include heating to a temperatureof about 200° C. to about 5000° C., about 700° C. to about 1500° C.,about 750° C. to about 1350° C., about 800° C. to about 1000° C., orabout 200° C. or less, or less than equal to, or greater than about 250°C., 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900,950, 1,000, 1,100, 1,200, 1,500, 1,750, 2,000, 2,500, 3,000, 3,500,4,000, or about 5,000° C. or more.

Heating of the abrasive composition can include raising the temperaturefrom room temperature to a maximum temperature over a prolonged periodof time (e.g., about 10 hours to about 130 hours) with optional holdingat one or more intermediate temperatures (e.g., for about 1 hour toabout 20 hours), holding at the maximum temperature (e.g., for about 1hour to about 20 hours), and then cooling the fired article to roomtemperature over an extended period of time (e.g., about 10 hours toabout 140 hours), with optional holding at one or more intermediatetemperatures (e.g., for about 1 hour to about 20 hours). The temperatureselected for the heating and the composition of the abrasive compositionshould be chosen so as to not have a detrimental effect on the physicalproperties and/or composition of the abrasive particles contained in theabrasive composition or the porous abrasive form.

Abrasive Composition.

Various embodiments of the present invention provide an abrasivecomposition. The abrasive composition includes pore inducers. Heating ofthe abrasive composition causes the pore inducers to reduce in volume,thereby generating pores in the formed porous abrasive form.

The abrasive composition can undergo an overall change in volume duringthe heating such that the volume of the porous abrasive form can begreater than or less than the volume of the abrasive composition. Theoverall change in volume can be unrelated to the change in volume of thepore inducers, such that a corresponding abrasive composition that isfree of the pore inducer undergoes a volume change upon subjecting toheating that is substantially the same as the volume change that occurswhen subjecting the abrasive composition including the pore inducers tothe same heating conditions. The abrasive composition can have a volumethat is about 1% to about 50% greater than the volume of the porousabrasive form, or about 10% to about 25% greater than the volume of theporous abrasive form, or about 0%, or about 1% or less, or less than,equal to, or greater than about 2%, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13,14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 28, 30, 32, 34, 36,38, 40, 45%, or about 50% or more.

The abrasive composition can include one type of pore inducer (whereinpore inducers can differ by composition, size, shape, or a combinationthereof) or more than one type of pore inducer. The one or more poreinducers can form any suitable weight proportion of the abrasivecomposition. The one or more pore inducers can be about 0.001 wt % toabout 50 wt % of the abrasive composition, about 5 wt % to about 20 wt %of the abrasive composition, or about 0.001 wt % or less, or less than,equal to, or greater than about 0.01 wt %, 0.1, 1, 2, 3, 4, 5, 6, 7, 8,9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 22, 24, 26, 28, 30, 35,40, 45, or about 50 wt % or more. The one or more pore inducers can formany suitable volume proportion of the abrasive composition, such asabout 0.001 vol % to about 50 vol % of the abrasive composition, about 5vol % to about 20 vol % of the abrasive composition, or about 0.001 vol% or less, or less than, equal to, or greater than about 0.01 vol %,0.1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19,20, 22, 24, 26, 28, 30, 35, 40, 45, or about 50 vol % or more.

The abrasive composition can include abrasive particles. The abrasivecomposition can include one type of abrasive particle, or more than onetype of abrasive particle. The one or more abrasive particles can formany suitable proportion of the abrasive composition, such as about 1 wt% to about 99 wt % of the abrasive composition, about 50 wt % to about95 wt %, or about 1 wt % or less, or less than, equal to, or greaterthan about 2 wt %, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35, 40, 45,50, 55, 60, 65, 70, 75, 80, 82, 84, 86, 88, 90, 91, 92, 93, 94, 95, 96,97, 98 wt %, or about 99 wt % or more. The abrasive particles caninclude a carbide, oxide (e.g., alumina, such as fused alumina),nitride, boride, diamond, ceramic, metal, glass, or a combinationthereof. The abrasive particles can be or can include abrasive grainsformed of a hard material (e.g., Mohs hardness of at least about 7). Theabrasive particles can include abrasive agglomerates, unagglomeratedabrasive particles, and combinations thereof. In some embodiments, theabrasive particles can include or be made of inorganic material such ascarbides, oxides, nitrides, borides, and combinations thereof. In someembodiments, the abrasive particles can be or include a superabrasiveparticulate material such as diamond or cubic boron nitride. In someembodiments, the abrasive particles can include or comprise ceramicparticles, including, for example, crystallites of alpha alumina,magnesium alumina spinel, and a rare earth hexagonal aluminate preparedusing sol-gel precursor alpha alumina particles. Other abrasiveparticles can include, fused aluminum oxide, treated aluminum oxide,white fused aluminum oxide, ceramic aluminum oxide materials such asthose commercially available under the trade designation 3M CERAMICABRASIVE GRAIN (from 3M Company of St. Paul, Minn.), black siliconcarbide, green silicon carbide, titanium diboride, boron carbide,tungsten carbide, titanium carbide, garnet, fused alumina zirconia,sol-gel derived abrasive particles, iron oxide, chromia, ceria,zirconia, titania, silicates, tin oxide, silica (such as quartz, glassbeads, glass bubbles, and glass fibers), silicates (such as talc, clays(e.g., montmorillonite), feldspar, mica, calcium silicate, calciummetasilicate, sodium aluminosilicate, sodium silicate), flint, emery,and combinations thereof. The abrasive particles can be or can includecrushed particulates and/or shaped particles (e.g., ceramic shapedabrasive particles). The abrasive particles can be coated (e.g., coatedwith a coupling agent), or can be free of coatings.

The abrasive composition can include a binder. The abrasive compositioncan include one binder, or more than one binder. The binder can bind theabrasive composition together. In some embodiments, the binder can bindthe abrasive composition together prior to the heating, but can less orno binding effect in the porous abrasive form (e.g., temporary binder,which can be decomposed or pyrolized during the heating). In someembodiments, the binder can undergo physical change (e.g., melting orsoftening, following by solidification and hardening) or chemical change(e.g., crosslinking or forming chemical bonds during curing) during theheating such that the binder binds together the porous abrasive form.The one or more binders can form any suitable proportion of the abrasivecomposition, such as about 1 wt % to about 80 wt % of the abrasivecomposition, about 5 wt % to about 20 wt %, or about 1 wt % or less, orabout 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19,20, 22, 24, 26, 28, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75 wt %, orabout 80 wt % or more of the abrasive composition.

Temporary binders can include dextrins (e.g., potato starch),polysaccharides, polyethylene glycol, polyacrylates, an adhesive, anorganic resin (e.g., urea/formaldehyde resin), a wax, or a combinationthereof.

Binders that have a binding effect in the porous abrasive form can beany suitable binder. The binder can be a glassy (e.g., vitreous)inorganic material (e.g., for a porous vitrified abrasive form), a metaloxide, a non-metal oxide, a silicate, a mineral, a metal, a curablecomponent (e.g., for a porous resinoid abrasive form), or a combinationthereof. The binder can be a vitreous binder (e.g., a glass materialsuch as a glass frit, or a material that forms a glass upon heating), anorganic resin, or a combination thereof.

Metal oxide vitreous binders can include silicon oxide, magnesium oxide,calcium oxide, barium oxide, lithium oxide, sodium oxide, potassiumoxide, iron oxide, titanium oxide, manganese oxide, zinc oxide, andmetal oxides that can be characterized as pigments such as cobalt oxide,chromium oxide, or iron oxide, and combinations thereof.

Non-metal oxides can include boron oxide, phosphorous oxide, andcombinations thereof. Suitable examples of non-metal compounds includeboric acid.

Silicates can include from aluminum silicates, borosilicates, calciumsilicates, magnesium silicates, sodium silicates, lithium silicates, andcombinations thereof.

Minerals can include clay, feldspar, kaolin, wollastonite, borax,quartz, soda ash, limestone, dolomite, chalk, and combinations thereof.

The curable component can be any suitable curable component, such as anycurable component described herein, such as a shellac, a polyamide, apolyester, a polycarbonate, a polycarbamate, a urethane, a naturalresin, an epoxy-based resin, a furan-based resin, a phenolic-basedresin, a urea/aldehyde resin, an acrylic, or a combination thereof.

During manufacture of a porous vitrified abrasive form, the vitreousbinder, in a powder form, may be mixed with a temporary binder,typically an organic binder. The vitrified binders may also be from afrit, for example anywhere from about 1 to 100 percent frit, butgenerally 20 to 100 percent frit. A frit can be a composition that hasbeen pre-fired prior to its employment in a vitreous bond precursorcomposition for forming the vitreous bond phase of a porous vitrifiedabrasive form. As used herein, a “frit” is a material that is formed bythoroughly blending a mixture comprising one or more fit formingcomponents, followed by heating (also referred to as pre-firing) themixture to a temperature at least high enough to melt it; cooling theglass, and pulverizing it. Some examples of common materials used infrit binders include feldspar, borax, quartz, soda ash, zinc oxide,whiting, antimony trioxide, titanium dioxide, sodium silicofluoride,flint, cryolite, boric acid, and combinations thereof. These materialscan be mixed together as powders, fired to fuse the mixture, and thenthe fused mixture can be cooled. The cooled mixture can be crushed andscreened to a very fine powder and then used as a first binder.

The abrasive composition can include any other suitable components, suchas a secondary pore inducer, a solvent (e.g., water, organic solvent,oil, or a combination thereof), a lubricant, a processing aid, a filler,a colorant (e.g., dye or pigment), an adhesive, or a combinationthereof.

Pore Inducers and Pores Formed Therefrom.

In various embodiments, the present invention provides a pore inducer.The pore inducer can be any suitable pore inducer that can be used toperform an embodiment of the method described herein. Upon heatingwithin a medium, such as within an abrasive composition, the poreinducer in the medium reduces in volume to form an induced pore in themedium. Although during the heating one or more components of the poreinducer may volatilize (e.g., transform to a gas via sublimation orboiling), these one or more components of the pore inducer are no longerin the medium and are not to be considered in the determination ofvolume reduction of the pore inducer in the medium. To determine thevolume reduction of the pore inducer in the medium, the beginning volumeof the pore inducer in the medium is compared to the final volume of theremaining pore inducer in the medium.

The induced pores in the porous abrasive form are aspects of theextrinsic porosity of the porous abrasive form. In contrast, theintrinsic porosity of the porous abrasive form can be independent of theextrinsic porosity, and can include pores caused by natural packinginefficiencies of various components of the porous abrasive form, glassbond degassing during firing, or other events natural to formation ofthe porous abrasive form. In various embodiments, intrinsic porosity canbe manipulated in the porous abrasive form, such as by modulating aspectratios of abrasive particles in the abrasive composition.

The induced pores in the porous abrasive form can substantiallycorrespond in shape and location to that of the pore inducers in theabrasive composition prior to the heating. The induced pores canapproximately correspond in size to that of the pore inducers in theabrasive composition prior to the heating. Each induced pore canindependently have a volume that is about 50% to about 100% of thevolume of the pore inducer in the abrasive composition prior to theheating that corresponds to the induced pore, or about 70% to about 95%,or about 50% or less, or less than, equal to, or more than about 55%,60, 65, 70, 72, 74, 76, 78, 80, 82, 84, 86, 88, 90, 91, 92, 93, 94, 95,96, 97, 98, 99%, or about 100%.

The present invention is not limited to any particular mechanism ofvolume reduction of the pore inducer during the heating of the abrasivecomposition to form the porous abrasive form. In some embodiments,during the heating one or more components of the pore inducers can meltor become flowable, such as a hollow component. When a hollow componentmelts or becomes flowable, the component can transform from a hollowshell that includes open space to a non-hollow shape or distributionthat has significantly reduced volume. In some embodiments, during theheating, one or more components of the pore inducers vaporize, sublime,decompose, pyrolize, or a combination thereof.

The pore inducers can have random shapes. The pore inducers can beshaped pore inducers, such that the pore inducers are three dimensionalgeometric shapes, such as the same shape or different shapes, such astetrahedrons, square pyramids, hexagonal pyramids, cubes, cuboids,triangular prisms, octahedrons, pentagonal prisms, hexagonal prisms,dodecahedrons, spheres, ellipsoids, icosahedron, cones, cylinders,sections of any one thereof, or any combination thereof.

The pore inducers can have any suitable size. The pore inducers can beequally sized, or the pore inducers can include more than one size. Thepore inducers can have a particle size (e.g., largest dimension) ofabout 0.1 micron to about 10,000 microns, or about 200 microns to about1,500 microns, or about 0.1 microns or less, or less than equal to, orgreater than about 1 micron, 2, 4, 6, 10, 15, 20, 25, 50, 100, 150, 200,250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900,950, 1,000, 1,050, 1,100, 1,150, 1,200, 1,250, 1,300, 1,350, 1,400,1,450, 1,500, 1,600, 1,700, 1,800, 1,900, 2,000, 2,250, 2,500, 2,750,3,000, 3,500, 4,000, 4,500, 5,000, 6,000, 7,000, 8,000, 9,000, or about10,000 microns or more.

The pore inducer can include a hollow glass filler. The hollow glassfiller can have any suitable shape such that a hollow space occurswithin the hollow glass filler particle. The hollow space can be closed(e.g., substantially sealed from the external environment) or open(e.g., not completely sealed from the environment, but still includes ahollow area and is sufficient to exclude surrounding materials from thehollow area). When a hollow glass filler melts or becomes flowable, thehollow glass filler can transform from a hollow shell that includes openspace to a non-hollow shape or distribution that has significantlyreduced volume. The hollow glass filler can be a glass bubble, or aglass sphere. The hollow glass filler can include any suitable type ofglass, such as soda-lime glass, fused silica glass, borosilicate glass,lead-oxide glass, aluminosilicate glass, oxide glass, glass with highzirconia content, or a combination thereof. The hollow glass filler caninclude borosilicate glass. A pore inducer can include one type ofhollow glass filler or more than one type of hollow glass filler. Theone or more hollow glass fillers can form any suitable proportion of thepore inducer, such as about 0.001 wt % to about 100 wt % of the poreinducer, about 1 wt % to about 30 wt %, or about 0.001 wt % or less, orless than, equal to, or greater than about 0.01 wt %, 0.1, 1, 2, 3, 4,5, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 35, 40, 45, 50, 55,60, 65, 70, 75, 80, 85, 90, 95, 96, 97, 98, 99 wt % or more, or about100 wt %. the hollow glass fillers can have any suitable particle size(e.g., largest dimension), such as about 0.1 micron to about 1,000microns, about 50 microns to about 100 microns, about 0.1 microns orless, or less than, equal to, or greater than about 1, 2, 3, 4, 5, 6, 8,10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95,100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 160, 170, 180,190, 200, 225, 250, 275, 300, 350, 400, 500, 600, 800, or about 1,000microns or more.

The pore inducer can include a cured component. The cured component canbe any suitable cured material. The cured component can be a curedresin, a cured latex, or a combination thereof. Pore inducer can includeone cured component or more than one cured component. The one of morecured components can form any suitable proportion of the pore inducer,such as about 1 wt % to about 99 wt % of the pore inducer, about 70 wt %to about 90 wt % of the pore inducer, or about 1 wt % or less, or lessthan, equal to, or greater than about 2 wt %, 3, 4, 5, 6, 8, 10, 15, 20,25, 30, 35, 40, 45, 50, 55, 60, 62, 64, 66, 68, 70, 72, 74, 76, 78, 80,82, 84, 86, 88, 90, 92, 94, 95, 96, 97, 98, 99 wt %, or about 100 wt %.The cured component of the pore inducer can be a cured product of ashellac, a polyamide, a polyester, a polycarbonate, a polycarbamate, aurethane, a natural resin, an epoxy-based resin, a furan-based resin, aphenolic-based resin, a urea/aldehyde resin, an acrylic, or acombination thereof. The cured component of the pore inducer can be acured product of bisphenol A diglycidyl ether resin, butoxymethyl butylglycidyl ether resin, bisphenol A-epichlorohydrin resin, bisphenol Fresin, or a combination thereof. The cured component of the pore inducercan be a cured product of an acrylic acid polymer, an acrylic acid esterpolymer, an acrylic acid homopolymer, an acrylic acid ester homopolymer,poly(methyl acrylate), poly(butyl acrylate), poly(2-ethylhexylacrylate), an acrylic acid ester copolymer, a methacrylic acidderivative polymer, a methacrylic acid homopolymer, a methacrylic acidester homopolymer, poly(methyl methacrylate), poly(butyl methacrylate),poly(2-ethylhexyl methacrylate), an acrylamidomethylpropane sulfonatepolymer or copolymer or derivative thereof, an acrylicacid/acrylamidomethylpropane sulfonate copolymer, or a combinationthereof. The cured component of the pore inducer can be a cured productof a trimer acid, a fatty acid, a fatty acid-derivative, maleicanhydride, acrylic acid, a polyester, a polycarbonate, a polycarbamate,an aldehyde, formaldehyde, a dialdehyde, glutaraldehyde, a hemiacetal,an aldehyde-releasing compound, a diacid halide, a dihalide, adichloride, a dibromide, a polyacid anhydride, citric acid, an epoxide,furfuraldehyde, an aldehyde condensate, a silyl-modified polyamide, acondensation reaction product of a polyacid and a polyamine, or acombination thereof. The cured component of the pore inducer can be acured product of at least one of an acrylate ester and an acrylic resin.The cured component of the pore inducer can be a cured product oftrimethylolpropane triacrylate, an acrylic resin, or a combinationthereof.

The pore inducer can include a plant material, such as one type of plantmaterial or more than one type of plant material. The one or more plantmaterials can form any suitable proportion of the pore inducer, such asabout 0.001 wt % to about 100 wt % of the pore inducer, about 1 wt % toabout 30 wt %, or about 0.001 wt % or less, or less than, equal to, orgreater than about 0.01 wt %, 0.1, 1, 2, 3, 4, 5, 6, 8, 10, 12, 14, 16,18, 20, 22, 24, 26, 28, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85,90, 95, 96, 97, 98, 99 wt % or more, or about 100 wt %. The plantmaterial can be a product from a shell, a seed, wood, or a combinationthereof. The plant material can be walnut shells, walnut shell flour,coconut shells, coconut shell flour, or a combination thereof.

The pore inducer can include a heat-volatile, heat-decomposable, orheat-pyrolizable component, such as one such component or more than onesuch component. The one or more heat-volatile, heat-decomposable, orheat-pyrolizable components can form any suitable proportion of the poreinducer, such as about 0.001 wt % to about 100 wt % of the pore inducer,about 1 wt % to about 30 wt %, or about 0.001 wt % or less, or lessthan, equal to, or greater than about 0.01 wt %, 0.1, 1, 2, 3, 4, 5, 6,8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 35, 40, 45, 50, 55, 60,65, 70, 75, 80, 85, 90, 95, 96, 97, 98, 99 wt % or more, or about 100 wt%. The heat-volatile, heat-decomposable, or heat-pyrolizable componentcan be a gel, naphthalene, a gamma-pyrone (e.g., ethyl maltol, methylmaltol, and the like), urea, a polyethylene, a polypropylene, apolyethylene glycol, a dextrin, a polysaccharide, a polyacrylate, anadhesive, a resin, or a combination thereof. The heat-volatile,heat-decomposable, or heat-pyrolizable material can be ethyl maltol.

Porous Abrasive Form.

In various embodiments the present invention provides a porous abrasiveform. The porous abrasive form can be any suitable porous abrasive formthat can be made using an embodiment of the method of forming a porousabrasive form described herein. The porous abrasive form can includepore inducers that have reduced in volume to form induced pores in theporous abrasive form. In the porous abrasive form, residual materialfrom the volume-reduced pore inducers can be present on or adjacent tothe inner surface of the pores therein. The residual material caninclude material in the pore inducer that melted, pyrolized, or degradedduring the heating to form the porous abrasive form, and can besubstantially free of material from the pore inducer that sublimed orvaporized during the heating.

The porous abrasive form can be any suitable form suitable for grindingor abrasion of a substrate. For example, the porous abrasive form can bean abrasive grinding wheel, a cut-off wheel, a hone, a whet stone, or acombination thereof. In some embodiments, the porous abrasive form canbe a porous vitrified abrasive form. In some embodiments, the porousabrasive form can be a porous resinoid abrasive form, or another type ofporous abrasive form.

The induced pores, other pores, or the combination thereof, can form anysuitable volume proportion of the porous abrasive form, such as about0.001 vol % to about 50 vol % of the porous abrasive form, about 5 vol %to about 20 vol % of the porous abrasive form, or about 0.001 vol % orless, or less than, equal to, or greater than about 0.01 vol %, 0.1, 1,2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 22,24, 26, 28, 30, 35, 40, 45, or about 50 vol % or more.

The porous abrasive form can have any suitable density, such as about1.3 g/cm³ to about 2.7 g/cm³, about 1.7 g/cm³ to about 2.0 g/cm³, orabout 1.3 g/cm³ or less, or less than, equal to, or greater than about1.4 g/cm³, 1.5, 1.55, 1.6, 1.65, 1.7, 1.75, 1.8, 1.85, 1.9, 1.95, 2,2.1, 2.2, 2.3, 2.4, 2.5, 2.6, or about 2.7 g/cm³ or more.

EXAMPLES

Various embodiments of the present invention can be better understood byreference to the following Examples which are offered by way ofillustration. The present invention is not limited to the Examples givenherein.

Unless otherwise noted, all parts, percentages, ratios, etc. in theExamples and the rest of the specification are by weight. Unless statedotherwise, all other reagents were obtained, or are available from finechemical vendors such as Sigma-Aldrich Company, St. Louis, Mo., or maybe synthesized by known methods.

Abbreviations and descriptions of materials used in the Examples arelisted in Table 1.

TABLE 1 TMPTA Trimethylolpropane triacrylate, obtained under tradedesignation “SARTOMER 351” from Sartomer Americas, Exton, Pennsylvania.PI α-Amino ketone photoinitiator, obtained under trade designation“IRGACURE 369” from BASF, Florham Park, New Jersey. AC1 Acrylic polymer,obtained under trade designation “ARKEMA ENCOR 651” from Arkema CoatingResins, Cary, North Carolina. AC2 Acrylic polymer, obtained under tradedesignation “ARKEMA ENCOR 357” from Arkema Coating Resins, Cary, NorthCarolina. AC3 Acrylic polymer, obtained under trade designation “ARKEMAENCOR 626” from Arkema Coating Resins, Cary, North Carolina. AC4 Acrylicpolymer, obtained under trade designation “ARKEMA ENCOR DT 211” fromArkema Coating Resins, Cary, North Carolina. AC5 Acrylic polymer,obtained under trade designation “NEOCAR ACRYLIC 820” from ArkemaCoating Resins, Cary, North Carolina. GB Glass bubbles, 70 μm, obtainedunder trade designation “Q-CELL 6028” from Potters Industries, ValleyForge, Pennsylvania. EM Ethyl maltol (C.A.S. # 4940-11-8), obtained fromSigma-Aldrich, St. Louis, Missouri. WS Walnut shell flour, #200 mesh,obtained as WF-5 from Composition Materials Company, Inc., Milford,Connecticut. PO Peanut oil, 2% in methanol. Peanut oil available fromArcher Daniels Midland Company, Chicago, Illinois. PT1 Polypropylenetool having a rectangular array of 333 mold cavities per square inch (52mold cavities per square cm) of top dimensions 0.0295 inches × 0.0295inches (0.75 millimeters (mm) × 0.75 mm), tapering inward at a 18 degreeangle on all sides, to a depth of 0.0300 inches (0.76 mm)(alternatively- tapering to a bottom dimension of 0.0200 inches × 0.0200inches (0.51 mm × 0.51 mm) at a depth of 0.0300 inches (0.76 mm). PT2Polypropylene tool having a rectangular array of 333 mold cavities persquare inch (52 mold cavities per square cm) of top dimensions 0.0295inches × 0.0295 inches (0.75 mm × 0.75 mm), tapering to a bottomdimension of 0.0200 inches × 0.0200 inches (0.51 mm × 0.51 mm) at adepth of 0.0300 inches (0.76 mm). AP1 White fused alumina abrasiveparticles, obtained under trade designation “DURALUM SPECIAL WHITE F54”from Washington Mills Electro Minerals, Niagara Falls, New York. AP2White fused alumina abrasive particles, obtained under trade designation“DURALUM SPECIAL WHITE F60” from Washington Mills Electro Minerals,Niagara Falls, New York. AP3 White fused alumina abrasive particles,obtained under trade designation “DURALUM SPECIAL WHITE F70” fromWashington Mills Electro Minerals, Niagara Falls, New York. AP4 Whitefused alumina abrasive particles, obtained under trade designation“DURALUM SPECIAL WHITE F320” from Washington Mills Electro Minerals,Niagara Falls, New York. V601 A glass frit blend. V904 A glass fritblend. NAP Naphthalene, CAS # 91-20-3, available from Sigma-Aldrich, St.Louis, Missouri. UFR A urea-formaldehyde resin, obtained under the tradedesignation “DURITE 3029c” from Momentive Specialty Chemicals, Inc.,Columbus, Ohio. TB1 Temporary binder, dextrin, obtained from AgranaStarke GmbH, Austria. TB2 A temporary binder resin that includes a UFRand optionally a wax component.

Example 1. Shaped Pore Inducer

A mixture of 99% by weight TMPTA and 1% PI (10 grams) was combined with2 grams of GB and thoroughly mixed with a spatula. PT1 was coated withPO and allowed to air dry. The TMPTA/PI/GB mixture (fill composition)was spread into the tooling cavities with a spatula. The filled tool wasthen placed (filled side up) on an aluminum support plate, a layer ofpolyethylene release film (obtained from Loparex Inc., Cary, N.C.) wasapplied to the top of the filled tool cavities, and a quartz panel wasplaced on the release film. The assembly was exposed to a UV lightsource used to cure the TMPTA. The tool containing the cured compositionwas then passed under an ultrasonic horn to dislodge the cured, shapedpore inducer. Photomicrographs of the shaped pore inducer are shown inFIGS. 1A-B. FIG. 1A shows the shaped pore inducers at 20× magnification.FIG. 1B shows the shaped pore inducers at 50× magnification. The shapedpore inducers had a maximum dimension of 720 microns.

Example 2. Shaped Pore Inducer

Example 2 was performed identically to Example 1 with the exception thatthe fill composition included 12 grams of the TMPTA/PI mixture, 2 gramsof GB, and 2 grams of EM.

Example 3. Shaped Pore Inducer

Example 3 was prepared identically to Example 1 with the exceptionsthat: 1) the thermally-curable fill composition included 10 grams of AC3and 2 grams of GB was substituted for the UV-curable fill composition;and 2) the filled tool was cured at 100 degrees F. (38 degrees C.) for 2hours (no UV cure).

Example 4. Comparative. NAP Pore Inducer

A NAP pore inducer was provided, which was random-shaped and having asize around 700 to 1400 microns.

Example 5. Vitrified Test Bars

Vitrified test bars were made with Comparative Example 4 NAP poreinducers using the following procedure: A composition of 18.35 gramsAP1, 45.87 grams AP2, 27.52 grams AP3, 8.26 grams V601, 0.95 grams TB1,3.55 grams TB2, and 10 grams NAP was thoroughly mixed. One-half (56grams) of the mixture was placed into and leveled with the top of asteel bar mold of rectangular cavity dimensions 120 mm×12 mm×50 mmheight, wherein a bottom punch extended into the bottom of the mold atthe time of filling about 13-15 mm. The mold was closed by inserting atop punch and pressed under a load of 3000 pounds (1361 kilograms. Thebar was removed from the mold and the procedure repeated to produce asecond bar. Each bar was then placed on loose AP4 and put into an ovenfor firing according to the schedule as shown in Table 2.

TABLE 2 Temperature, ° C. Rate, ° C./minute room temperature to 420 +2420 for 4 hours 0 420-700 +2 700 for 4 hours 0 700-900 +2 900 for 4hours 0 900 to room temperature −5

Scanning electron microscope (SEM) micrographs of the resulting pores invitrified test bars are shown in FIGS. 2A-B. The vitrified test bar hada density of 1.77 g/cm³.

Vitrified test bars were made following the same procedure except that10 grams of the shaped pore inducer of Example 1 was used instead of theNAP pore inducers. The resulting vitrified bars had uniformly shapedpores distributed evenly throughout the bar. SEM micrographs of theresulting pores in the vitrified test bar are shown in FIGS. 3A-C. FIGS.4A-B illustrate photomicrographs of the vitrified test bar, with FIG. 4Aat 2× magnification, and with FIG. 4B at 20× magnification. The physicalproperties of the vitrified test bar are shown in Table 3.

TABLE 3 Physical properties of vitrified test bar. Before firing Afterfiring Weight 56.0 g 49.5 g Height 18.25 mm 18.25 mm Thickness 12 mm 12mm Length 120 mm 120 mm Density 2.131 g/mm3 1.884 g/cm3

The terms and expressions that have been employed are used as terms ofdescription and not of limitation, and there is no intention in the useof such terms and expressions of excluding any equivalents of thefeatures shown and described or portions thereof, but it is recognizedthat various modifications are possible within the scope of theembodiments of the present invention. Thus, it should be understood thatalthough the present invention has been specifically disclosed byspecific embodiments and optional features, modification and variationof the concepts herein disclosed may be resorted to by those of ordinaryskill in the art, and that such modifications and variations areconsidered to be within the scope of embodiments of the presentinvention.

Additional Embodiments

The following exemplary embodiments are provided, the numbering of whichis not to be construed as designating levels of importance:

Embodiment 1 provides a method of forming a porous abrasive form, themethod comprising:

heating an abrasive composition comprising pore inducers, to form theporous abrasive form, wherein during the heating the pore inducers inthe porous abrasive form reduce in volume to form induced pores in theporous abrasive form.

Embodiment 2 provides the method of Embodiment 1, wherein the porousabrasive form is an abrasive grinding wheel, a cut-off wheel, a hone, awhet stone, or a combination thereof.

Embodiment 3 provides the method of any one of Embodiments 1-2, furthercomprising forming the abrasive composition.

Embodiment 4 provides the method of any one of Embodiments 1-3, furthercomprising forming the pore inducers.

Embodiment 5 provides the method of Embodiment 4, wherein forming thepore inducers comprises curing a pore inducer starting materialcomposition, to provide the pore inducers.

Embodiment 6 provides the method of Embodiment 5, wherein forming thepore inducers further comprises placing the pore inducer startingmaterial composition in a mold prior to the curing, wherein the curingis performed while the pore inducer starting material composition is inthe mold, further comprising removing the pore inducers from the moldafter the curing.

Embodiment 7 provides the method of any one of Embodiments 1-6, whereinthe abrasive composition is a pressed abrasive composition.

Embodiment 8 provides the method of any one of Embodiments 1-7 furthercomprising pressing the abrasive composition prior to the heating.

Embodiment 9 provides the method of Embodiment 8, wherein the pressingcomprises a pressure of about 0.001 kg/mm² to about 1,000 kg/mm².

Embodiment 10 provides the method of any one of Embodiments 8-9, whereinthe pressing comprises a pressure of about 0.1 kg/mm² to about 10kg/mm².

Embodiment 11 provides the method of any one of Embodiments 1-10,wherein the induced pores substantially correspond in shape and locationto that of the pore inducers in the abrasive composition prior to theheating.

Embodiment 12 provides the method of any one of Embodiments 1-11,wherein the induced pores approximately correspond in size to that ofthe pore inducers in the abrasive composition prior to the heating.

Embodiment 13 provides the method of Embodiment 12, wherein the inducedpores have a volume that is about 50% to about 100% of the volume of thepore inducers in the abrasive composition prior to the heating.

Embodiment 14 provides the method of any one of Embodiments 12-13,wherein the induced pores have a volume that is about 70% to about 95%of the volume of the pore inducers in the abrasive composition prior tothe heating.

Embodiment 15 provides the method of any one of Embodiments 1-14,wherein during the heating one or more components of the pore inducersmelt or become flowable.

Embodiment 16 provides the method of any one of Embodiments 1-15,wherein during the heating one or more components of the pore inducersvaporize, sublime, decompose, pyrolize, or a combination thereof.

Embodiment 17 provides the method of any one of Embodiments 1-16,wherein the abrasive composition undergoes volume contraction during theheating to form the porous abrasive form.

Embodiment 18 provides the method of Embodiment 17, wherein the abrasivecomposition has a volume that is about 1% to about 50% greater than thevolume of the porous abrasive form.

Embodiment 19 provides the method of any one of Embodiments 17-18,wherein the abrasive composition has a volume that is about 10% to about25% greater than the volume of the porous abrasive form.

Embodiment 20 provides the method of any one of Embodiments 1-19,wherein the heating comprising vitrifying, wherein the porous abrasiveform comprises a porous vitrified abrasive form.

Embodiment 21 provides the method of any one of Embodiments 1-20,wherein the heating comprises a temperature of about 200° C. to about5000° C.

Embodiment 22 provides the method of any one of Embodiments 1-21,wherein the heating comprises a temperature of about 800° C. to about1000° C.

Embodiment 23 provides the method of any one of Embodiments 1-22,wherein the pore inducers are about 0.001 wt % to about 50 wt % of theabrasive composition.

Embodiment 24 provides the method of any one of Embodiments 1-23,wherein the pore inducers are about 5 wt % to about 20 wt % of theabrasive composition.

Embodiment 25 provides the method of any one of Embodiments 1-24,wherein the pore inducers are shaped pore inducers.

Embodiment 26 provides the method of any one of Embodiments 1-25,wherein the pore inducers are three dimensional geometric shapes.

Embodiment 27 provides the method of any one of Embodiments 1-26,wherein the pore inducers are tetrahedrons, square pyramids, hexagonalpyramids, cubes, cuboids, triangular prisms, octahedrons, pentagonalprisms, hexagonal prisms, dodecahedrons, spheres, ellipsoids,icosahedron, cones, cylinders, sections of any one thereof, or anycombination thereof.

Embodiment 28 provides the method of any one of Embodiments 1-27,wherein the pore inducers have a particle size of about 0.1 micron toabout 10,000 microns.

Embodiment 29 provides the method of any one of Embodiments 1-28,wherein the pore inducers have a particle size of about 200 microns toabout 1,500 microns.

Embodiment 30 provides the method of any one of Embodiments 1-29,wherein the pore inducer comprises a hollow glass filler.

Embodiment 31 provides the method of Embodiment 30, wherein the hollowglass filler is about 0.001 wt % to about 100 wt % of the pore inducer.

Embodiment 32 provides the method of any one of Embodiments 30-31,wherein the hollow glass filler is about 1 wt % to about 30 wt % of thepore inducer.

Embodiment 33 provides the method of any one of Embodiments 30-32,wherein the hollow glass filler is a hollow glass sphere.

Embodiment 34 provides the method of any one of Embodiments 30-33,wherein the hollow glass filler has a particle size of about 0.1 micronto about 1,000 microns

Embodiment 35 provides the method of any one of Embodiments 30-34,wherein the hollow glass filler has a particle size of about 50 micronsto about 100 microns.

Embodiment 36 provides the method of any one of Embodiments 30-35,wherein the hollow glass filler comprises soda-lime glass, fused silicaglass, borosilicate glass, lead-oxide glass, aluminosilicate glass,oxide glass, glass with high zirconia content, or a combination thereof.

Embodiment 37 provides the method of any one of Embodiments 30-36,wherein the hollow glass filler comprises borosilicate glass.

Embodiment 38 provides the method of any one of Embodiments 1-37,wherein the pore inducer comprises a cured component.

Embodiment 39 provides the method of Embodiment 38, wherein the curedcomponent of the pore inducer is a cured resin, a cured latex, or acombination thereof.

Embodiment 40 provides the method of any one of Embodiments 1-39,wherein the cured component of the pore inducer is about 1 wt % to about99 wt % of the pore inducer.

Embodiment 41 provides the method of any one of Embodiments 1-40,wherein the cured component of the pore inducer is about 70 wt % toabout 90 wt % of the pore inducer.

Embodiment 42 provides the method of any one of Embodiments 38-41,wherein the cured component of the pore inducer is a cured product of ashellac, a polyamide, a polyester, a polycarbonate, a polycarbamate, aurethane, a natural resin, an epoxy-based resin, a furan-based resin, aphenolic-based resin, a urea/aldehyde resin, an acrylic, or acombination thereof.

Embodiment 43 provides the method of any one of Embodiments 38-42,wherein the cured component of the pore inducer is a cured product of atleast one of an acrylate ester and an acrylic resin.

Embodiment 44 provides the method of any one of Embodiments 38-43,wherein the cured component of the pore inducer is a cured product oftrimethylolpropane triacrylate, an acrylic resin, or a combinationthereof.

Embodiment 45 provides the method of any one of Embodiments 1-44,wherein the pore inducer comprises a plant material.

Embodiment 46 provides the method of Embodiment 45, wherein the plantmaterial is about 0.001 wt % to about 100 wt % of the pore inducer.

Embodiment 47 provides the method of any one of Embodiments 45-46,wherein the plant material is about 1 wt % to about 30 wt % of the poreinducer.

Embodiment 48 provides the method of any one of Embodiments 45-47,wherein the plant material comprises a product from a shell, a seed,wood, or a combination thereof.

Embodiment 49 provides the method of any one of Embodiments 45-48,wherein the plant material comprises walnut shells, walnut shell flour,coconut shells, coconut shell flour, or a combination thereof.

Embodiment 50 provides the method of any one of Embodiments 1-49,wherein the pore inducer comprises a heat-volatile, heat-decomposable,or heat-pyrolizable component.

Embodiment 51 provides the method of Embodiment 50, wherein theheat-volatile, heat-decomposable, or heat-pyrolizable component is about0.001 wt % to about 100 wt % of the pore inducer.

Embodiment 52 provides the method of any one of Embodiments 50-51,wherein the heat-volatile, heat-decomposable, or heat-pyrolizablecomponent is about 1 wt % to about 30 wt % of the pore inducer.

Embodiment 53 provides the method of any one of Embodiments 50-52,wherein the heat-volatile, heat-decomposable, or heat-pyrolizablecomponent is a gel, naphthalene, a gamma-pyrone, urea, a polyethylene, apolypropylene, a polyethylene glycol, a dextrin, a polysaccharide, apolyacrylate, an adhesive, a resin, or a combination thereof.

Embodiment 54 provides the method of any one of Embodiments 50-53,wherein the heat-volatile, heat-decomposable, or heat-pyrolizablematerial is ethyl maltol.

Embodiment 55 provides the method of any one of Embodiments 1-54,wherein the abrasive composition further comprises abrasive particles.

Embodiment 56 provides the method of Embodiment 55, wherein the abrasiveparticles are about 1 wt % to about 99 wt % of the abrasive composition.

Embodiment 57 provides the method of any one of Embodiments 55-56,wherein the abrasive particles are about 50 wt % to about 95 wt % of theabrasive composition.

Embodiment 58 provides the method of any one of Embodiments 55-57,wherein the abrasive particles comprise a carbide, oxide, nitride,boride, diamond, ceramic, metal, glass, or a combination thereof.

Embodiment 59 provides the method of any one of Embodiments 55-58,wherein the abrasive particles comprises fused alumina.

Embodiment 60 provides the method of any one of Embodiments 1-59,wherein the abrasive composition further comprises a binder.

Embodiment 61 provides the method of Embodiment 60, wherein the binderis about 1 wt % to about 80 wt % of the abrasive composition.

Embodiment 62 provides the method of any one of Embodiments 60-61,wherein the binder is about 5 wt % to about 20 wt % of the abrasivecomposition.

Embodiment 63 provides the method of any one of Embodiments 60-62,wherein the binder is a glassy inorganic material, a metal oxide, anon-metal oxide, a silicate, a mineral, a metal, a curable component, ora combination thereof.

Embodiment 64 provides the method of any one of Embodiments 60-63,wherein the binder is a vitreous binder, an organic resin, or acombination thereof.

Embodiment 65 provides the method of any one of Embodiments 1-64,wherein the abrasive composition, further comprises a secondary poreinducer.

Embodiment 66 provides the method of any one of Embodiments 1-65,wherein the porous abrasive form has a density of about 1.3 g/cm³ toabout 2.7 g/cm³.

Embodiment 67 provides the method of any one of Embodiments 1-66,wherein the porous abrasive form has a density of about 1.7 g/cm³ toabout 2.0 g/cm³.

Embodiment 68 provides a porous vitrified abrasive form made by themethod of any one of Embodiments 1-67.

Embodiment 69 provides a method of forming a porous vitreous abrasiveform, the method comprising:

heating an abrasive composition comprising pore inducers comprisinghollow glass filler, to form the porous vitreous abrasive form, whereinduring the heating the pore inducers in the porous vitreous abrasiveform reduce in volume to form induced pores in the porous vitreousabrasive form.

Embodiment 70 provides a porous abrasive form comprising:

pore inducers that have reduced in volume to form induced pores in theporous abrasive form.

Embodiment 71 provides a pore inducer, wherein upon heating within amedium the pore inducer in the medium reduces in volume to form aninduced pore in the medium

Embodiment 72 provides the method, porous abrasive form, or pore inducerof any one or any combination of Embodiments 1-71 optionally configuredsuch that all elements or options recited are available to use or selectfrom.

What is claimed is:
 1. A method of forming a porous vitreous abrasive form, the method comprising: molding a pore inducer staring material composition to form a plurality of hollow glass filler pore inducers with a 3D geometric shape and a size, wherein each of the plurality of pore inducers have the same 3D geometric shape and size; heating an abrasive composition comprising pore inducers comprising the molded hollow glass filler pore inducers, to form the porous vitreous abrasive form; and wherein during the heating the pore inducers in the porous vitreous abrasive form reduce in volume to form induced pores in the porous vitreous abrasive form, wherein the induced pores comprise a shape similar to the 3D geometric shape.
 2. The method of claim 1, wherein the pore inducers comprise a heat-volatile, heat-decomposable, or heat-pyrolizable component.
 3. The method of claim 1, wherein the abrasive composition, further comprises a secondary pore inducer.
 4. The method of claim 1, wherein the porous vitreous abrasive form has a density of about 1.3 g/cm³ to about 2.7 g/cm³.
 5. The method of claim 1, wherein the pore inducers are tetrahedrons, square pyramids, hexagonal pyramids, cubes, cuboids, triangular prisms, octahedrons, pentagonal prisms, hexagonal prisms, dodecahedrons, spheres, ellipsoids, icosahedron, cones, cylinders, sections of any one thereof or any combination thereof.
 6. The method of claim 1, wherein during the heating one or more components of the pore inducers melt or become flowable.
 7. The method of claim 1, wherein the induced pores approximately correspond in size to that of the molded pore inducers in the abrasive composition prior to the heating.
 8. The method of claim 7, wherein the induced pores have a volume that is about 50% to about 100% of the volume of the molded pore inducers in the abrasive composition prior to the heating.
 9. The method of claim 7, wherein the induced pores have a volume that is about 70% to about 95% of the volume of the molded pore inducers in the abrasive composition prior to the heating. 